Switch



M r 1932- T. BIRKENMAIER ET KL ,2

swmcn Filed April 21, 1928 2 Sheets-Sheet 1 Maid! 1933 T. BIRKENMAIER ET AL SWITCH Filed April 21 1928 2 Sheets-Sheet 2 Patented Mar. 8, 1932 i UNITED STATES PATENT OFFICE THEODORE BIRKRNMAIER, or s'r. LOUIS, LEsTR PIERCE BOLL, OF MAPLEWOOD, A-ND IIR BERTH. W FRLE OF S'LLOUIS, MIssoURI, ASSIGNORS TO w. N. MATTHEWS OORI'ORATIOm F ST. LOUIS, MISSOURI, A CORPORATION or MISSOURI SWITCH Application filed Apri121,

This invention relates to switches, and with may be noted the provision of an improved type of a fuse switch of maximum simplicity and ruggedness having a configuration including no hinge pins or lugs for the switch per se, nor fastening bosses; the provision of a switch of the class described having simplified door controlling means; and the provision of a fuse switch of the class-described in which there is minimum danger of the current path being shortenedbetween contacts. Other objects will be in part obvious andin part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts which will be exemplified in the structurehereinafter described, and the scope of the application of'which will be indicated in the following claims. H I V In the accompanying drawings, in which is illustrated one of various possible embodiments of the invention, I,

Fig. 1 is a vertical section taken through a closed switch box and fuse cartridgecomprising the invention; p

Fig. 2- is a front elevation of Fig. 1, certain portions being broken away;

Fig. 3 is a bottom plan view of Fig; 1;

Fig. 4 is a view similarto Fig. 1, showing the door'open and a fuse cartridge in partially removed position; and,

Fig. 5 is a cross section taken on line 5'5 of Fig. 1.

Similar reference characters indicate corresponding parts throughout the several views of the drawings.

Referring now more particularly to Fig. 1, there is illustrated at numeral 1 a box, composed of non-conducting material, preferably of porcelain. The box in its finished commercial form is preferably of a unitary construction, the various members thereof being baked together and comprising aback 3, a backwa'rdly sloping top 5, side walls 7 and a septum 9. Recesses 11 are provided in the rear for cementing on suitable supporting 192 s .seria1 170. 271,770.

of which a better enclosing effect is had. The

door '15 is hingedat the top of the box by meansof a pin 17 At its lower end it is provided with, an external finger piece 19 for opening and closing purposes.

One of the novel features of the invention comprises a pair of resilient detents 21 fastened to the upperend of said door 15. The

detents are preferably formed with a cross strip 22 for fastening purposes. Each detent is preferably of curved form and is positioned nearly flush with the inner faces of the side walls 7 of the box, except that it has a bent portion 23, the effect of which portion '23 is to press against the sai'd'in'ner faces so as thereby frictionally hold the door shut.

Also when the door is drawn open, as illustrated in Fig. 4, then the'bent or curved portions 23 of-the detents spring outwardly and drop into their respective longitudinal door recesses 13. The door is thus held in open position. Theeconomy of this construction is apparent, because it may be seen thatthe same recesses 13"that serve as a door stop and to more completely close the box against weath er, also serve as recesses for the action of the 'detents 21.

set screws. for wire holding purposes. The

pair of set screws provided for each socket 27 may be used with either passage 31, whereby wires maybe brought in from either side of the switch through eithereombination of openings 33, or; from one side only.

The spring clips 29 are of the type adapted to spring the detents 21 slightly inward and to receive therebetween in electrical contact the flat sided terminal engaging elments 35 of the fuse cartric go C. The cartridge includes the upper element 35 having screw means 37 thereon for holding a fuse wire 88 in electrical contact. This upper element is also formed with a bridge portion 39 for hooking on an insulated tool 40 for removing and applying the cartridge. A long, gas-expulsive insulating tube a1 is fastened to the upper engaging element 35 and surrounds said fuse link 38 down to a hair pin turn 43 on the latter.

The insulating tube ll passes with a snug fit through the lower terminal engaging element It is not held to the same with any device such as a set screw, because these have been found to damage the tube and promote leakage, so that an are (such as is formed upon blowing connects the terminals over the shortest possible distance, namely through the portion of the tube ll between said terminals.

Next to the long tube 4L1 is a short insulating tube 45 which is held to the lower terminal 35 by means of a set screw 47. A pin ll) composed of fiber or other insulating material is then placed through a rearward extension 51 of the lower terminal 35 in such a way as to partially intersect the material of both tubes 41, 45. The intersection is not enough to completely perforate the two walls Fig.

The function of the intersecting pin 49 is to prevent the long tube ell from turning or dropping, inasmuch as said tube has only a frictional engagement with the lower term inal Hence the previous weakness of having a set screw engage the tube 41 is eliminat- The fact that the tubes 41 and %5 are engaged by set screws at the terminals themselves makes no material difference because possible current leaka e at those points will not shorten the effective are.

The lower terminal 35 has an upper extension 51 which serves as a fastening for the fuse, fastening being accomplished by means of the screw plug A further improvement of the lower terminal 35, taken in connection with the septum 9, consists in said lower and rearward extension 51, which in effect comprises two follower lugs 55, one on each side of the tube ll. These lugs engage the upper forwardly sloping surface of the septum 9. This upper surface, composed of porcelain, similar to the remainder of the box, is preferably glazed and is therefore smooth. it is to be understood that the septum may be constructed of other material sucl as fiber, bakelite or other insulating material.

The septum 9 is provided with an opening 57 having an upper beveled portion 59 for wardly and a lower beveled portion 61 rearwardly, said opening being adapted to receive the lower ends of the tubes 1-1, 45 snugly but not tightly. The fit between the lower end of the cartridge and said opening 57, when the latter is canted forwardly (Fig. 4), is rather loose, while when the cartridge is in vertical or terminal engaging position, the .tlt is snug enough to substantially separate the interior and exterior of the box.

It will be seen that the septi'un not at the lowermost region of the box 1 but is raised somewhat, so that when the cartridge is in terminal engaging position, then the lower end of the cartridge, for purposes of protection, is within the confines of the back 3, side walls 7 and door 15.

The switch may be supplied with a fuse cartridge by opening the door to the Fig. 4; position and inserting the lower end of the cartridge through the opening in the septum as illustrated in The lugs limit the degree of insertion. This is an easy op eration because the fit is loose.

When the lugs strike the septum, the operator pushes the cartridge back into the l 1 position with the terminal engaging elements 35 within the confines of the terminals 29. At this time the lugs ride up on the sloping septum with the cartridge pivoting at point X (Fig. l) so that there is always attained a proper and accurate engagement. No high dog a skillnorcarcnceds be exercised in. pushing home the cartridge.

Removal effected by aoplying the tool hook at bridge and drawing down the cartridge. It pivots on the hu until con tact broken and then A forward to a position slightly beyond the l -l position. After this the cartridge may be oulled out of the septum opening 57 by hand or with the tool.

The advantage of this construction is that no hinge pins or the like are used for swing ing the *artridge. It greatly simplifies the nninufacture. Also, the cartridge is positively placed in a position where the lower open ends of the tubes are or. :side of the box, so that when the cartridge blows gases are not engendered within the box.

It is to be understood that a double tube type of fuse or switch cartridge is not the only one which may be used with the invauniou herein set forth. Single tube and tubeless cartridges may be used as well multi-tubed ones of any number of tubes, the primary requisite being a proper fuse mounting.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As many changes could be made in carrying out the above constructions without dcparting from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanynals therein, a fuse cartridge having termi-' nal engaging elements,'a septum in the box having an opening therein adapted to receive therethrough one end of said cartridge and means on the cartridge adapted to engage said septum to be guided therebyto guide the terminal engaging elements into the line terminals. I i

2. A switch comprising a box, line terminals therein, a fuse cartridge having terminal engaging elements, a forwardly sloping septum in the box having an opening therein adapted to receive therethrough one endof said cartridge and means on the cartridge adapted to engage said septum to be guided upwardly thereby to guide the terminal engaging elements into the line terminals, whereby said cartridge may be moved angularly to permit insertion and removal.

3. A switch comprising a box, line terminals therein, an expulslve fuse cartridge having terminal engaging elements, a septum in the box having an opening therein adapted to receive therethrough the expulsive end of said cartridge to permit angular movement of the cartridge, said septum being located at a distance above the lower edges of thebox and having a slope, and means on the cartridge engaging. the septum for movement of said cartridge.

4. A switch comprising a box, line terminals therein, a fuse cartridge having terminal engaging elements, a septum in the box having an opening therein adapted to receive therethrough one end of the cartridge and means comprising an integral-part of one of said terminal engaging elements adapted to engage said septum to be guided thereby, said box, including the septum, being composed of insulating material.

5. In a switch box, a switch cartridge for use in the box, a septum for the box having an opening therein adapted to receive a part of the cartridge so as to permit angular swinging thereof, the contour of said openin being such as to permit free movement of t e cartridge under conditions of application but to substantially separate the inside of the box from the outside thereofin connection with the cartridge when said cartridge is positioned entirely within the box and guiding means on the cartridge for engaging said septum.

guiding the V tridge having terminal engaging elements, line terminals within the box adapted to be engaged by said terminal engaging elements,

a forwardly sloping septum for the box at its lower end, a door for the box hinged at the upper end, said septum having an opening therein adapted to receive therethrough the expulsive end of the cartridge, the contour of said opening being such, as to permit free movement of the cartridge under conditions of application but to substantially separate the inside of the box from the outside thereof in connection with the cartridge when said cartridge is positioned entirely within the box, said opening functioning as a fulcrum and guiding means on the cartridge for engaging said septum, whereby the en aging elements are guided to cooperate with t e line terminals.

8. In a switch box, a box portion having forward edges, recesses in said edges, a door hinged to the front of the box having extending portions engaging said recesses, at least one spring detent on said door engaging the inner wall of the box and adapted to spring into one of said recesses upon opening the door.

9. A switch box of the class described comprising a unitary porcelain box, a door therefor, said box comprising a back, top, side walls and a sloping bottom, said bottom comprising a septum completely defining independently of said door an opening adapted to receive a cartridge or the like, and line ter-. minals inthe box, said complete definition of the opening by the bottom providing a reaction portion for eflecting engagement of a cartridge with said line terminal.

In testimony whereof, we have signed our names to this specification this 18th day of April, 1928. I

THEODORE BIRKENMAIERL LESTER PIERCE BOLL. HERBERT H. WEFELER.

6. In a switch box, a switch cartridge for i use in the box, a septum for thebox having an opening therein adapted to receive apart of the cartridge so as to permit angular swinging thereof and to function as a fulcrum therefor and means on the cartridge engaging said septum for guiding-purposes.

7. In a switch box, an expulsive fuse -,car-' 

